A nondestructive technique for screening of pHEMT epi in
order to comply with electrical specification criteria is discussed. The 300K
PL spectra deconvolution and the spectra differences were used to track the
sheet charge Ns in the InGaAs channel. The PR aproach to AlGaAs Schottky layer
composition and charge is applied for production wafer screening. The
correlation with PCM device results was used to create a pass/fail filter for
pHEMT epi.